The present invention is directed, in general, to a method of manufacturing a bipolar transistor and, more specifically, to a method of converting a metal oxide semiconductor (MOS) transistor into a bipolar transistor.
The advent of the integrated circuit has had a significant impact on various types of communication devices. The integrated circuit has been incorporated into both radio frequency applications and high speed communication network systems. While operating speeds of these communication devices have dramatically increased, the demand for yet faster communication devices continues to rise.
Bipolar devices have been used throughout the years for applications requiring high speed/high current drive, as well as low noise. Bipolar devices are especially desirable because they may be used in conjunction with traditional metal oxide semiconductor (MOS) technologies, providing an integrated circuit that yields the desired high speed/high current capabilities, as well as the equally desired lower speed/lower current capabilities. However, while bipolar devices are currently able to provide the high speed/high current capabilities presently desired, bipolar devices experience certain drawbacks that limit their use.
One such drawback is the high cost of manufacturing bipolar devices. Because of the techniques required to manufacture bipolar devices, bipolar devices are much more expensive to manufacture than traditional MOS devices. In many instances it may require an additional 6 to 8 masking steps to manufacture a bipolar device, as compared to a traditional MOS device. While lithography has been improved over the years, becoming less time consuming and expensive, it still comprises a substantial portion of the manufacturing expenses associated with producing integrated circuit devices.
Accordingly, what is needed in the art is a bipolar transistor and a method of manufacture therefor, which provides the high speed/high current characteristics generally desired, however, that is much easier and less expensive to manufacture than the prior art bipolar devices.
To address the above-discussed deficiencies of the prior art, the present invention provides a method of manufacturing a bipolar transistor. The method includes producing an opening in a dielectric layer located over a substrate, and forming a collector in the substrate by implanting a first dopant through the opening. The method further includes creating an intrinsic base region contacting the collector, and constructing an emitter contacting the intrinsic base region, both of which are achieved through the opening.
The present invention is further directed to a method of manufacturing an integrated circuit, including fabricating more than one of the previously described bipolar transistors, and connecting the bipolar transistors to form an operative integrated circuit. In another aspect, the present invention provides a bipolar transistor. The bipolar transistor includes (1) a collector located in a substrate, (2) an intrinsic base region located in the collector, (3) source/drain regions contacting the intrinsic base region and located outside of the collector, and (4) an emitter located on the substrate over the intrinsic base region.
The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.